The invention relates to a method of determining the target direction and target range of sound generating targets, such wheeled or track-laying vehicles, with the aid of a sensing arrangement composed of a plurality of sensors including acoustic sensors to determine the target direction, i.e. the target bearing angle.
For the full realization of area defense mines, sensors are required which reconnoiter potential targets (wheeled and track-laying vehicles) with sufficient accuracy so that the ammunition can be used effectively. As a function of the deployment system (throwing system, etc.) and the ammunition (e.g., conventional ammunition, target sensing ammunition) target range and direction must be determined. Typical distance ranges are--depending on the design of the ammunition--40 to 300 m.
German Patent No. 3,140,728 discloses, for example, a method of determining the target direction and target range in which the target is detected by means of an airborne sound sensor composed of four microphones. The range is determined with the aid of an active target sensor composed of a sound source and the mentioned airborne sound sensor. The primary drawback of this arrangement is that the target detection device itself must include a sound source. Moreover, such active sensors are easy to detect.
German Patent No. 3,601,053 discloses an actuator arrangement for a rigid directional mine including a laser range finder. In this case as well, an active sensor is involved which is easy to detect.
DE-OS German Offenlegungsschrift (printed unexamined application) 3,705,981 discloses a device for detecting a target and initiating ignition that includes a seismic sensor and an acoustic sensor composed of two directional microphones and in this case, the seismic sensor serves to activate the directional microphones, and thus constitutes a so-called prompting sensor. The bearing angle is then determined with the aid of the directional microphones. The target range is not measured by this prior art device.
Finally, DE-OS German Offenlegungsschrift (printed unexamined application) 3,804,495 discloses an electronic ignition device for antitank mines which includes a seismic sensor and three magnetic field sensors. In this case again, the seismic sensor serves as a prompting sensor.